School-desk



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No. 750,527. PATENTED JAN. 26, 1904.

J. F. FIELD. A

SCHOOL DESK.

APPLICATION FILED 1123.19, 1902.

N0 MODEL. 2 SHEETS-SHEET 2.

ateted january 26, 1904;

PATENT OFFICE. i

JOHN F. FIELD, OF CHICAGO, ILLINOIS.

SCHOOL-DESK.

SPECIFICATION forming part of Letters Patent No. 750,527, dated January26, 1904. Application filed April 19, 1902. Serial No. 103,708. (Nomodel.) i

To` @ZZ whom, it may con/cern.:

Beit known that I, JOHN F. FIELD, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in School-Desks; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

This-invention relates to the class of schooldesks in which a desk andseat are combined and supported on the same legs or standards and areadapted to have a vertical adjustment with reference to each other inbringing the same to the required elevation for use. Under the ordinaryarrangement the combined desk and seat structure is provided with anadjusting device that is a permanent part of such structure, and onemust be provided for each combination desk and seat, which addsconsiderably to the original cost.

The object, therefore, of this invention is to provide a simpleindependent attachment for lowering or raising the desks and seats andwhich may be readily attached and detached, so that one device may beused on any number of desks and the possibility of the desks or seatsbeing changed by mischievous scholars entirely avoided.

In the drawings, Figure 1 is a view in perspective of a combination deskand seat structure which embodies the improved features. Fig. 2 is ahorizontal section on line 2, Fig. 1. Fig. 3 is an elevation and partsection on a line dividing the desk and seat looking at the back of thedesk, and Fig. 4 is a detached plan of the adjusting attachment.

A represents a desk, and B a seat adjustably combined and which may beof the ordinary construction.

The legs or standards 5 and 6 are adjustably secured to the oppositesides of the structure andare each provided with the vertical slots 7and 8. A clamping-bolt 9 is inserted in the slot 7 and has its inner endfixed in the adjacent part of the desk. A nut 10 has a threadedengagement with the outer end of bolt 9 and serves to lock the bolt atany point within the range of the slot 7 and support the desk at the theseat part.

required elevation. A companion bolt 11 is inserted through slot 8 andis rigidly secured in the adjacent part of the seat structure. Alocking-nut 12 has a threaded engagement with bolt 11 and holds the samein any position to which it may be moved in raising or lowering It willbe understood that the slots, bolts, and nuts are duplicated in the legsat the opposite side.

The adjusting attachment' comprises a pair of levers 13 and 14, pivotedtogether near their longitudinal center, as at a, and have an openingand closing movement at both ends similar to the action of a pair ofshears. These levers are shown in their crossed working position in Fig.3, the inner end of lever 13 loosely engaging a shoulder-bearing 15 andthe outer end a shoulder -bearing 16, both forming an integral part ofthe desk part. The inner end of lever 14 engages the lower shoulder 17and the outer end the upper shoulder 18. The outer ends of thesecompanion levers are connected by an adjusting screwrod 19, having aright and left handed thread from the center outward in the direction ofeach end. The companion nuts 20 are pivotally secured in the respectiveouter ends of the companion levers. The screw-rod has a threadedengagement with these `nuts and opens and closes the levers inaccordance with the direction in which the screw-rod is turned. One orboth ends of the screw rod may be provided with a square end to receivea suitable manipulating handle or crank, as the device may be insertedeither side up. By turning the screw-rod in one direction the ends ofthe levers are spread and the desk or seat raised in accordance to whichpart of the device is attached, and when turned in the oppositedirection the levers are contracted and the desk or seat lowered. rIheinner ends of the levers are provided with a number of notches 21, whichprevent an endwise Inovement and also adapt the device for use on desksof different widths.

It will be noted that this portable device may be slipped in and out ofits working position with the greatestfacility and but a Inoments timeis required in changing from one desk to another.

IOO

In practical Working the device should be first inserted to support theweight of the desk or seat, next the locking-nuts on the clampingboltsshould be loosened, when the desk may be raised or lowered as requiredand the locking-nuts set up, when the adjusting attachment may beremoved for use on other desks as may be required.

Having thus described Iny invention, what I claim as new, and desire tosecure by Letters Patent, is-

l. The combination with a joint school-desk and seat structure, ofsupporting legs or standards provided with vertical slots andclampingbolts inserted in said slots and engaging the desk and seatparts and locking the same at any elevation within the range ofadjustment, the companion crossed levers having a detachable operativeconnection in their working position, and means for expanding orcontracting said levers in changing the relative elevations of the deskand seat parts, substantially as set forth.

2. A portable attachment for adjusting the elevation of combination deskand seat structures, comprising a pair of levers pivoted together neartheir longitudinal center in a crossed position, a screw-rod, and meansfor securing said screw-rod to the adjacent ends of said levers, wherebythe respective ends of the levers may be expanded or contracted inaccordance With the direction in which the screw-rod is turned,substantially as set forth.

3. A school desk and seat adjusting attachment, comprising a pair oflevers pivoted together in a crossed position, the threaded nuts,pivotally seated in the outer ends thereof, a screw-rod having a rightand left hand thread and engaging said nuts, and means for rotating saidrod in spreading or contracting said levers, substantially as set forth.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHN F. FIELD.

Witnesses:

J. B. DoNALsoN, L. B. CoUrLAND.

